The C6337A570 is a MicroLogic 7.3 E AL electronic trip unit for the Schneider Electric ComPacT NSX400...630 range, rated 570 A at 40 °C. It protects three poles (3P) with LSI curves: long-time (L) for overload, short-time (S) for short-circuit with adjustable delay, and instantaneous (I) for high faults. The integrated earth-leakage protection (Class A) means it detects ground faults without a separate module — one less component to wire and troubleshoot on the DIN rail. That certification covers the trip unit's breaking performance, coordination, and endurance — it's the spec that tells a site engineer the part is accepted in most industrial and commercial distribution panels globally.
Protection and metering in one package
The MicroLogic 7.3 E AL does more than trip curves. It includes an energy meter (type of measurement: Energy meter) and communicates protection and alarm settings, time-stamped event logs, power quality data, demand current, and earth-leakage readings. The LCD display shows local signalling: a flashing green LED for ready, red at 105% Ir for overload, orange at 90% Ir as a pre-alarm. Adjustable protection settings give flexibility for coordination. Long-time pickup (Ir) adjusts from 250 to 570 A. Short-time pickup (Isd) from 1.5 to 10 x Ir, with delay adjustable 0 to 0.4 s (I²t on or off). Instantaneous pickup (Ii) from 1.5 to 11 x In. That range lets you tune selectivity with downstream breakers — set the short-time delay long enough to let a feeder breaker clear a fault before this unit trips, keeping the rest of the bus live.
Integration into the ComPacT NSX frame
The trip unit mounts into a fixed-mount ComPacT NSX400...630 circuit breaker (circuit breaker mounting mode: Fixed). It's a front-accessible electronic unit — no need to pull the breaker from the panel to swap settings or replace the trip unit. The 3D protected poles (3D) mean all three phases are monitored for earth leakage, not just one. IP40 front face (conforming to IEC 60529) handles typical panel dust; the back of the breaker in the enclosure is the sealed side. Network frequency is 50/60 Hz, rated operational voltage 440 V AC. Earth-leakage protection can be switched OFF via the IΔn rotary switch — useful during commissioning to avoid nuisance trips on startup inrush, then turned on for normal operation. The trip unit is electronic, not thermal-magnetic, so it holds its calibration over temperature and doesn't drift with age like a bimetal strip.